Automatic analyzer and sample-processing system

ABSTRACT

A sample-processing system that improves total system processing efficiency, and reduces a sample-processing time, by establishing a functionally independent relationship between a rack conveyance block with rack supply, conveyance, and recovery functions, and a processing block with sample preprocessing, analysis, and other functions. A buffer unit with random accessibility to multiple racks standing by for processing is combined with each of multiple processing units to form a pair, and the system is constructed to load and unload racks into and from the buffer unit through the rack conveyance block so that one unprocessed rack is loaded into the buffer unit and then upon completion of process steps up to automatic retesting, unloaded from the buffer unit. Functional dependence between any processing unit and a conveyance unit is thus eliminated.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates generally to sample-processing systems.More particularly, the invention relates to a sample-processing systemsuitable for efficient operation of a plurality of analyzers differentin functionality and in processing capabilities and interconnected usinga conveyor line to convey sample racks.

2. Description of the Related Art

Analytical results on blood plasma, serum, urine, and other biologicalsamples provide large volumes of useful information for diagnosingmedical conditions, and there are a large number of conventionaltechniques relating to analyzers intended for automatic processing ofsuch biological samples.

JP-A-10-19899, for example, discloses a technique on which is based anautomatic analyzer that includes a plurality of analytical units eachequipped with transfer means for loading a rack into the analyticalunit, with transfer means provided independently of the former transfermeans in order to unload the rack from the analytical unit, and withdiscrimination means provided on the upstream side of the analyticalunit in order to discriminate a request item for a sample. The analyzer,after judging which of the multiple analytical units is to be used toanalyze the sample, assigns a rack-loading instruction to an appropriateanalytical module.

Also, JP-A-10-213586 describes an automatic analyzer equipped with aplurality of analytical units along a belt conveyor line, with a racksupply unit at one end of the conveyor line, and with a rack recoveryunit at the other end of the conveyor line. A standby unit for causingracks to stand by for processing is further disposed in front of therack recovery unit so as to allow automatic retesting.

In addition, JP-A-279357 describes an automatic analyzer in which astandby disc for causing racks to stand by for processing is disposed ona rack conveyance route between a rack supply unit and an analyticalunit, the standby disc being provided for avoiding congestion on therack conveyance route and for automatic retesting.

SUMMARY OF THE INVENTION

In the automatic analyzer of JP-A-10-19899, a rack conveyance route isdetermined before the rack is conveyed to the analytical unit. Whenanalysis by multiple analytical units is required, therefore, sincesamples will be conveyed in order from the upstream side, if there are alarge number of samples to be analyzed on the upstream side, the rackconveyance route will become congested and none of any samples to beanalyzed only on the downstream side will be able to move past a sampleexisting upstream.

In the automatic analyzer of JP-A-10-213586, although a return route isprovided to convey racks from the downstream side to the upstream side,when a rack is conveyed to a downstream analytical unit first, it willbe absolutely necessary that the rack, before being conveyed to anupstream analytical unit, be returned to the rack supply unit located atthe uppermost position of the upstream side. In addition to consumingtime, such a conveying sequence will obstruct the processing of theracks supplied from the supply unit.

Additionally, the samples that require automatic retest will beconcentrated at the standby unit in front of the recovery unit. In asystem configuration with a plurality of analytical units each differentin processing rate, therefore, even when a rack is present that containssamples whose analytical results have already been output and which areto undergo retests, an unnecessary waiting time will occur since thatrack will be unable to pass a rack that has entered the standby unitearlier. Furthermore, for retesting, the rack will need to be returnedto the rack supply unit similarly to the above, so the conveyingsequence in this case as well will correspondingly consume time andobstruct the processing of the racks supplied from the supply unit.

In the automatic analyzer of JP-A-279357, although the rack standby unithas circular disc construction and is therefore excellent in randomaccessibility to racks, a dead space occurs on the disc since the racksthemselves are of a general shape close to a rectangle. Also, the deadspace in the entire system due to the use of the circular disc is large.

Additionally, in a system configuration with a plurality of analyticalunits, since the rack is conveyed to a downstream analytical unitthrough the standby disc, the direction of the rack becomes inverse andthe traveling direction of the rack needs to be returned to its originaldirection in front of the next analytical unit.

An object of the present invention is to provide a sample-processingsystem optimized in terms of total system process flow by assigning onlya rack conveyance function to a rack supply unit, a conveying unit, anda recovery unit, as their intended purpose, and assigning all othercharacteristic and necessary functions of processing units to each ofthe processing units.

Among major problems associated with conventional techniques is that therack conveyance unit has a functional block that the standby unit andother analytical units require.

A system according to the present invention includes a buffer unit thatcauses a plurality of racks to stand by for processing and has randomaccessibility to each rack, and the buffer unit is combined with each ofmultiple processing units to form a pair. The system is also constructedto load/unload each rack into/from the buffer unit. One unprocessed rackis loaded into the buffer unit and then upon completion of process stepsup to automatic retesting, the rack is unloaded from the buffer unit.Functional dependence between any processing unit and a rack conveyanceunit is thus eliminated.

In addition, if a rack transfer block that uses the buffer unit totransfer racks to and from a rack conveyance block is constructed to beable to access both a feed route and return route of the racks conveyedby the rack conveyance unit, minimizing a conveying distance betweenprocessing units allows the system to start the earliest executableprocess first, without being aware of the layout order of multipleprocessing units, even when the kind of processing of a particularsample spans the multiple processing units. This, in turn, makes itunnecessary to determine the entire rack conveyance route on theupstream side of the system. In addition, upon completion of processingin one processing unit, loads of other processing units can beconfirmed, so the rack can be conveyed to the processing unit whose loadis the lightest of all processing unit loads. A processing time of theentire system is reduced as a result.

A sample-processing system optimized in terms of total system processflow can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a configuration diagram of a sample-processing systemaccording to an embodiment of the present invention;

FIG. 2 is a functional block diagram of the system configuration of FIG.1;

FIG. 3 is a configuration diagram of a sampler unit in the embodiment ofthe present invention;

FIG. 4 is a configuration diagram of a load rack-moving mechanism of thesampler unit;

FIG. 5 is a block diagram of a buffer unit in the embodiment of thepresent invention;

FIG. 6 is a block diagram and operational illustrative diagram showing arack transfer mechanism of the buffer unit;

FIG. 7 is another block diagram and operational illustrative diagramshowing the rack transfer mechanism of the buffer unit;

FIG. 8 is yet another block diagram and operational illustrative diagramshowing the rack transfer mechanism of the buffer unit;

FIG. 9 is a further block diagram and operational illustrative diagramshowing the rack transfer mechanism of the buffer unit;

FIG. 10 is a further block diagram and operational illustrative diagramshowing the rack transfer mechanism of the buffer unit;

FIG. 11 is a further block diagram and operational illustrative diagramshowing the rack transfer mechanism of the buffer unit;

FIG. 12 is a further block diagram and operational illustrative diagramshowing the rack transfer mechanism of the buffer unit;

FIG. 13 is a further block diagram and operational illustrative diagramshowing the rack transfer mechanism of the buffer unit;

FIG. 14 is a further block diagram and operational illustrative diagramshowing the rack transfer mechanism of the buffer unit;

FIG. 15 is an illustrative diagram of rack conveyance between the bufferunit and a functional module;

FIG. 16 is an illustrative diagram of rack conveyance between the bufferunit and a supplemental module;

FIG. 17 is a flowchart of rack conveyance route determination;

FIG. 18 is an illustrative diagram of the rack flow in the embodiment ofthe present invention;

FIG. 19 is another illustrative diagram of the rack flow in theembodiment of the present invention; and

FIG. 20 is an illustrative diagram of emergency-test sample loading rackflow.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

An embodiment of the present invention will be described hereunder.

FIG. 1 is a plan view of a sample-processing system according to anembodiment of the present invention. The system shown as an example inFIG. 1 includes: a sampler unit 100 for loading and storing a samplerack; a rack conveyance unit 200 for conveying the sample rack betweenthe sampler unit and the functional modules; buffer units 300 a and 300b (second buffer unit) each disposed along the rack conveyance unit 200,for transferring the sample rack to and from the rack conveyance unit200 and for causing temporary standby of the sample rack; functionalmodules 400 a and 400 b each paired with the buffer unit 300 a or 300 band located to the right thereof; and a supplemental module 500 locatedto the left of the buffer unit 300 a.

FIG. 2 shows the system of FIG. 1 in functionally classified form. Inthis case, constituent elements of the system can be classified into afunctional block 1 including the buffer unit 300 a, the functionalmodule 400 a, and the supplemental module 500 in order to undertakesample analysis, preprocessing, and other processes, a functional block2 including the buffer unit 300 b and the functional module 400 b, and asample rack conveyance block 3 including the sampler unit 100 and therack conveyance unit 200. The functional block 1, the functional block2, and the conveyance block 3 deliver and receive sample racks to andfrom each other at connections 4 and 5.

While the functional blocks in the present embodiment are eachconstructed of a buffer unit and a functional module, a functionalmodule including a buffer unit therein is also embraced in the presentinvention.

Also, the functional block 1, the functional block 2, and the conveyanceblock 3 are constructed so that input and output sections required foreach will be connected to equipment of related facilities independentlyof each other. In addition, except for processes relating to theexchange of sample racks between the three blocks, that is, physicalmovement of each sample rack, issuance of processing requests concerningsamples, transmission of results, and exchange of other information, thefunctional blocks 1, 2 and the conveyance block 3 are constructed to beoperable in completely independent form.

Each constituent unit of the system, and total system operation will bedescribed hereunder.

A configuration of the sampler unit 100 is shown in FIG. 3.

The sampler unit 100 includes: a loader 101 for loading a sample rackinto the system; a storage section 102 for unloading sample racks fromthe system; a load rack moving unit 103 for transferring a loaded samplerack from the loader to the rack conveyance unit 200; a rack ID readingunit 104 for reading identification (ID) information assigned to thesample rack; a sample vessel height detection unit 105 for confirmingwhether sample vessels are set up on the sample rack, and detecting theheight of each sample vessel; a sample ID reading unit 106 for reading,for example, an ID label of the sample, affixed to the sample vessel setup on the sample rack; a sample vessel rotating unit 107 for rotatingthe sample vessel during the reading of the sample ID; an unload rackmoving unit 108 for moving the rack from the rack conveyance unit 200 tothe storage section 102; an emergency-test sample loader 109 for loadingan emergency-test sample rack into the sample-processing system or forloading thereinto a sample rack conveyed from a rack conveyance systemconnected on the upstream side of the sample-processing system; and arack unloader 110 for unloading the sample rack into the rack conveyancesystem connected on the upstream side of the sample-processing system.

The loader 101 includes a loading tray setup unit 121 in which to set upa sample rack tray capable of being hand-carried with a plurality ofsample racks set up thereon, and a loading buffer 122 disposed betweenthe tray setup unit and the load rack moving unit 103. The loader 101also has a loading lever 123 functioning as a driving mechanism toconvey the sample racks in a Y-direction. In addition, the loader 101has a loading mechanism 124 (see FIG. 4) that is adapted to rotate theloading lever axially in the Y-direction.

After a sample rack tray has been set up in the loading tray setup unit121, the loading mechanism 124 activates a rotating motor 125 to rotatethe loading lever 123, and drives a moving motor 126 to move the samplerack tray in the Y-direction. The sample racks on the tray are thusconveyed to the load rack-moving unit 103 through the loading buffer122. After all racks have moved out from the loading buffer 122, theloading mechanism 124 rotates the loading lever 123. The lever thenreturns to a required sample rack tray setup position and stands by forthe next sample rack tray to be set up thereat.

Upon completion of the movement of all sample racks from the sample racktray to the loading buffer 122, the sample rack tray is removable, thusallowing setup of the next sample rack tray. In this case, after movingout all racks from the loading buffer 122, the loading lever 123 of theloading mechanism 124 usually conducts a rack-loading process upon thesample rack tray that has been newly set up in place. Instead, however,the loading process for the sample racks in the loading buffer 122 canbe interrupted using a switch (not shown) that is provided on thesampler unit 100, or in accordance with an operator instruction from ascreen of an operating unit. After the interruption, the loading lever123 can be returned to the load tray setup position 121 in order torestart the feed operation for the racks on the sample rack tray.

In addition, the present embodiment has two sample-loading units, andwhen the rack feed operation by one of the units is completed and allracks are gone from the particular unit, the other unit conducts a rackfeed operation. While the present embodiment has two sample-loadingunits, processing in an arrangement of more than two units also advancessimilarly.

After receiving the rack from the loading unit, the load rack movingunit 103 transfers the rack to the rack ID reading unit 104, by whichthe ID of the rack is then read and the rack is further transferred tothe sample vessel height detection unit 105.

The sample vessel height detection unit 105 confirms whether samplevessels are set up in internal positions of the sample rack, and detectsthe height of each sample vessel.

After this, the sample rack is moved to a sample ID reading position, atwhich the IDs of each sample are then read by the sample ID reading unit106. A sample-vessel rotating unit 107 is equipped at the sample IDreading position.

In general, bar codes are used as sample IDs. Also, cups, test tubes,test tubes each with a cup thereupon, or other various kinds of objectsare used as sample vessels. The bar codes as sample IDs, because of adimensional requirement for each to have a necessary amount ofinformation, are usually labeled onto test tubes only. During theprocessing of samples, therefore, whether the sample ID is to be readand whether the sample vessel is to be rotated are judged from theforegoing rack ID information and sample vessel height information.

Necessary processes for the sample rack are determined from the aboverack ID and sample ID information. Also, functional modules aredetermined as conveyance destinations.

After the conveyance destinations of the sample rack have beendetermined, the load rack-moving unit 103 moves the rack to the rackconveyance unit 200.

An emergency-test sample rack or a sample rack from a sample conveyancesystem connected on the upstream side of the sampler unit 100 is loadedfrom the emergency-test sample loader 109 into the sampler unit. Therack that has been loaded from the emergency-test sample loader 109undergoes substantially the same kind of processing as that of theabove-described rack loaded from the sample loader 101, and then movesto the rack conveyance unit 200.

Also, the sample rack that has gone through the necessary processes ineach functional module is moved to the storage section 102 by the unloadrack moving unit 108.

As with the loader 101, the storage section 102 includes an unloadingtray setup unit 131 in which to set up a sample rack tray capable ofbeing hand-carried with a plurality of sample racks set up thereon, andan unloading buffer 132 disposed between the loading tray setup unit andthe load rack moving unit 103. An unloading lever 133 for conveying thesample racks in a Y-direction is also equipped as a driving mechanism.

The sample racks that have been conveyed to a front area of the storagesection 102 by the unload rack moving unit 108 are conveyed to theunloading buffer 132 through a load rack moving lane by the unloadinglever 133, and when the unloading buffer 132 is filled with as manysample racks as mountable on one sample rack tray, the racks are eachmoved to the tray.

Instead, the sample racks in the unloading buffer 132 can be moved tothe sample rack tray in the unloading tray setup unit 131 by operating aswitch (not shown) that is provided on the sampler unit 100, or bysending an operator instruction from a screen of an operating unit (notshown).

The sample-processing system further has the rack unloader 110 forunloading a sample rack into the sample conveyance system connected onthe upstream side of the sample-processing system. The rack unloader 110is of a size adapted for holding one rack, and is also constructed to beslidable in a Y-direction so that a position for Y-axial unloading ofthe rack into the sample conveyance system can be changed.

The rack conveyance unit 200 in FIG. 1 has two rack conveyance lanes,namely, a feed lane 201 for conveying sample racks from the sampler unit100 to the functional modules 400 a, 400 b, and a return lane 202 forconveying the sample racks from the functional modules 400 a, 400 b tothe sampler unit 100. The rack conveyance unit 200 also has a beltmechanism 210, a stopper mechanism 220 (220 a, 220 b), and a shuttermechanism 230, as shown in FIG. 5.

The belt mechanism 210 uses conveyor belts to convey the sample racksbetween the sampler unit 100 and the functional modules 400 a, 400 b,along the feed lane 201 and the return lane 202. In the presentembodiment, one conveyor belt is used for the feed lane and the returnlane each, and conveyor belt-driving motors 211 a, 211 b andbelt-tensioning mechanisms 212 a, 212 b are respectively equipped at aterminatory section of the rack conveyance unit 200. This scheme allowsrapid sample rack conveyance. Also, this scheme is suitable for a systemwith a random-conveyance ability to convey sample racks to a pluralityof functional modules or bi-directionally between the functional modulesarranged on the upstream and downstream sides of the system. Although nodescription is given in the present embodiment, this scheme may besuitable for a processing system in which, as in a sample preprocessingsystem, the same sample rack stops at a plurality of functional modules,for example, centrifuging, decapping, and pipetting modules in orderfrom the upstream side of the system to the downstream side to undergoprocessing. In that case, a plurality of conveyor belts with a lengthequal to the width of each functional module are arranged in series, andduring processing, the sample rack is delivered and received betweenadjacent conveyor belts. It is desirable, therefore, that an appropriatemechanical configuration of belts be selectable to suit a particularconfiguration of the system and necessary processing capabilitiesthereof.

The stopper mechanism 220 for stopping the sample rack at predeterminedpositions on sample rack loading routes to each functional module has astopper 220 a for the feed lane 201 and a stopper 220 b for the returnlane 202.

The shutter mechanism 230 has a total of three vertically movable rackguide plates, two for rack guiding on the feed lane 201 and one for rackguiding on the return lane 202, and moves downward only for sample rackunloading into each functional module or for sample rack loadingtherefrom.

A configuration of a buffer unit 300 is shown in FIG. 5.

The buffer unit 300 including a rack-unloading standby section 301, abuffer 302, a cold-storage section 303, a module loading/unloadingstandby position 304, a rack conveyance section/line 310, a one-rackloader/unloader 320, and an ID reader 321, moves the sample rack viarack-unloading mechanisms 370 and 371.

The rack-unloading standby section 301 is a position having a space forcausing one rack to stand by, and at this standby position, the samplerack from the rack conveyance unit 200 is transferred to the buffer unit300. This standby position is also where a sample rack to be unloadedfrom the buffer unit 300 into the rack conveyance unit 200 is made tostand by.

The buffer 302 further includes a plurality of independent slots in eachof which a sample rack can be made to stand by temporarily.

The cold-storage section 303 is constructed so that a plurality ofsample racks, each containing accuracy management samples or othersamples that require periodic processing in the functional modules, canbe made to stand by inside. The cold-storage section 303 has acold-storage function to prevent these samples from evaporating.

The module loading/unloading standby section 304 is a position having aspace for causing one rack to stand by, and at this standby position,the sample rack from the buffer unit 300 is unloaded into the functionalmodule 400. This standby position is also where a sample rack that hasundergone processing in the functional module is loaded into the bufferunit 300.

The rack conveyance section 310 conveys the sample rack between themodule loading/unloading standby position 304 and the functional module400.

The one-rack loader/unloader 320 functions as a sample loader/unloaderfor processing the sample rack in the functional module withoutinvolving the rack conveyance unit 200.

A rack transfer mechanism 330 transfers the sample rack bi-directionallyin a Y-direction between the rack loading/unloading standby section 301and the feed lane 201 of the rack conveyance unit 200, and between therack loading/unloading standby section 301 and the return lane 202. Forsample rack transfer in one direction only, the sample rack can usuallybe moved horizontally if the rack conveyance surface height existingafter the rack has been moved is adjusted to be slightly smaller thanthe rack conveyance surface height existing before the rack is moved. Inthe present system, however, the transfer mechanism 330 also needs tohave a function that lifts the rack in a Z-direction, becausebi-directional movement is required and because the rack needs to crossthe feed lane 201 to move to and/or from the return lane 202.

The rack transfer mechanism 300 is further detailed below using FIGS. 6to 10. Rack transfer from the feed lane 201 of the rack conveyance line200 to the rack loading/unloading standby section 301 is taken as anexample in the description.

The rack transfer mechanism 330 includes a gripper 340 and a Y-mover350. The gripper 340 has a function that opens/closes two grippingplates in a Y-direction to grip the rack, and a function that lifts thegripped rack in a Z-direction. The Y-mover 350 moves the gripper in theY-direction.

The gripper 340 includes a pulley 343 that transmits driving force usinga motor 341 and a belt 342, a rotating shaft 344 of the pulley, twogripping plates 346 fitted with cam followers 345 and movable verticallyin the Z-direction, and a spring 347 that works in a direction to drawthe gripping plates 346 closer to the spring. Also, the pulley 343 hastwo bearings 348 and the rotating shaft 344 of the pulley has a steppedcam 349.

The buffer unit 300 activates a driving motor 351 of the Y-mover 350 inthe rack transfer mechanism 330, thus moving the gripper 340 to the feedlane 201 of the rack conveyance line 200 in order to load a sample rack.At this time, the gripper 340 is in an open condition, that is, with thetwo gripping plates 346 pushed open by the two bearings 348 fitted inthe pulley 343, and with the cam followers 345 and the cam 349 not incontact with each other.

The rack conveyance unit 200 drives the stopper 220 a disposed at therack transfer position in the buffer unit 300, and protrudes the stopperabove the feed lane 201. After this, the rack conveyance unit 200 drivesa motor 211 a of the belt mechanism 210 and moves the sample rack.

The gripper 340 rotates the pulley 343 by driving the motor 341 to gripthe sample rack that has stopped at the transfer position. The rotationof the gripper moves the bearings 348, closes the two gripping plates346 in the Y-direction by the pulling force of the spring 347, and gripsthe sample rack, as shown in FIG. 7. Further rotation of the motor 341brings the bearings 348 into a non-contact state with respect to thegripping plates 346, thus moving the cam followers 345 onto an elevatedsection of the cam, as shown in FIG. 8, and consequently moving the twogripping plates 346 upward to allow rack lifting in the Z-direction.

After the gripper 340 has lifted the sample rack in the Z-direction, therack conveyance unit 200 drives a motor of the shutter 230 and moves theshutter 231 downward.

After the shutter 231 has moved downward, the rack transfer mechanism330 drives the motor 351 of the Y-mover and moves the sample rack in theY-direction for transfer to the rack loading/unloading standby section301.

Upon completion of the sample rack transfer, the rack conveyance unit200 returns the stopper 220 a from the feed lane and moves the shutter230 upward for the next sample rack transfer.

After the movement of the sample rack to the rack loading/unloadingstandby section 301, the gripper 340 releases the gripped condition ofthe sample rack. This operation is conducted by rotating the motor 341in an inverse direction relative to the rotating direction for grippingthe rack, and the release is conducted in order reverse to that ofgripping.

While the gripper in the present embodiment is constructed to lift thesample rack in operational association with the opening/closingoperation of the gripping plates by driving one motor, substantially thesame effect can be obtained by providing an independent motor for thegripping plate opening/closing operation and the rack-lifting operationeach.

A rack-moving mechanism 360 includes a bucket 361 adapted to hold onerack and move in the Y-direction, an X-mover 362 that moves in theY-direction with the bucket to move the internal rack thereof in anX-direction, and a vertically movable carriage 363 installed in theX-mover 362.

The rack-moving mechanisms are further detailed below using FIGS. 11 to14 with the sample rack transfer from the rack loading/unloading standbysection 301 to the buffer 302 taken as an example in the description.

First, the rack-moving mechanism 360 drives a Y-driving motor 364 tomove the bucket 361 to the position of the rack loading/unloadingstandby section 301, as shown in FIG. 11. At the same time, therack-moving mechanism 360 also drives an X-driving motor 365 to move thecarriage 363 of the X-mover 362 to a position under the sample rack inthe rack loading/unloading standby section 301, and after the carriage363 has moved to a position at which the carriage gets into a bottomgroove of the sample rack, moves a Z-driving motor 366 to move thecarriage upward, as shown in FIG. 12.

The bucket 361 and a sample rack conveyance surface of the rackloading/unloading standby section 301 both have a slit 367 to make thecarriage 363 movable in an upward moved condition in the X-direction. Alike slit is also provided in the buffer 302, the cold-storage section303, and other sections using the rack-moving mechanism 360 to move thesample rack.

Next, the rack-moving mechanism 360 moves the carriage 363 under thebucket 361 by driving the X-driving motor 365 to move the sample rack tothe bucket, as shown in FIG. 13.

After the sample rack has been moved to the bucket 361, the rack-movingmechanism 360 drives the Y-driving motor 364 to move the bucket 361 to adestination slot in the buffer 302. At this time, the carriage 363remains in an upward position to prevent the rack in the bucket frommoving in the X-direction and sliding out from the bucket.

After the bucket has moved to the slot in the buffer 302, therack-moving mechanism 360 moves the carriage 363 under the slot bydriving the X-driving motor 365 to move the sample rack to the slot, asshown in FIG. 14.

In the present embodiment, rack movement from the rack loading/unloadingstandby section 301 to the bucket 361 has been described. Sample racksare also moved from other sections such as the buffer 302 orcold-storage section 303 to the bucket 361 in essentially the samemanner. In addition, while rack movement from the bucket 361 to thebuffer 302 has been described, sample racks are moved to thecold-storage section 303, the module loading/unloading standby position304, and other sections, in essentially the same manner. Constructingother sections so as to have independent standby slots for sample racksallows random accessing of any rack.

Next, transferring a sample rack from the buffer unit 300 to thefunctional module 400 is described below using FIG. 15.

The sample rack transferred to the functional module 400 is moved to themodule loading/unloading standby position 304 by the rack-movingmechanism 360, and further moved to the rack conveyance section 310 bythe rack-unloading mechanism 370.

The rack conveyance section 310 takes a mechanical configurationsuitable for the functional module involved. An example in which thefunctional module 400 is of a type that draws the sample rack from therack conveyance section into the functional module and after executionof a necessary process such as pipetting, returns the sample rack to therack conveyance section, is described in the present embodiment. Also,the functional module in the embodiment has a buffer capable of holdinga plurality of racks in series inside.

The sample rack that has been moved to the rack conveyance section 310by the rack-unloading mechanism 370 is moved on to a sample rack loadingposition 401 in the functional module by the rack-moving mechanism. Therack-moving mechanism here can be a belt mechanism such as the rackconveyance line 200, or can be a mechanism such as a carriage.

The sample rack that has been drawn into the functional module 400 by arack-loading mechanism thereof (not shown) is moved to a processingposition 402 to undergo the necessary process such as pipetting. Duringthis process, if a following sample rack to be processed in thefunctional module 400 is present, the buffer unit 300 moves the samplerack to the functional module via the rack conveyance section inessentially the same sequence. The functional module then causes thesample rack to stand by at a buffer position 403 in the module.

After being processed in the functional module 400, the sample rack isonce again returned to a rack-unloading position 404 on the rackconveyance section 310 by a rack-unloading mechanism not shown. Therack-moving mechanism moves the sample rack in a direction inverse tothat of the transfer of the rack to the functional module 400, thusunloading the rack into the module loading/unloading standby position304.

In the present embodiment, sample racks move bi-directionally betweenthe buffer unit 300 and the rack conveyance section 310, and rackloading/unloading to/from the buffer unit 300 is controlled according tothe number of racks which can be held in the buffer of the functionalmodule 400. In other words, sample rack unloading from the buffer unit300 is continued until the buffer of the functional module 400 hasbecome full, but after the buffer has become full, the sample rackreturned from the functional module 400 will be loaded into the bufferunit 300, so the module loading/unloading standby position 304 is leftempty and after the sample rack from the functional module 400 has movedinside the buffer unit 300, the next sample rack is moved to the moduleloading/unloading standby position 304 and conveyed to the functionalmodule 400 via the rack conveyance section 310.

An example in which the functional module internally has a bufferfunction to hold a plurality of racks in series with respect to theprocessing position has been described in the present embodiment.However, essentially the same processing results can be achieved by, forexample, using either a functional module of a type to and from whichthe sample rack can be loaded and unloaded at the same position in themodule, or a functional module of a type in which the necessary processsuch as pipetting can be conducted on the conveyance line withoutinvolving rack loading/unloading. In that case, although the mechanicalconfiguration of the rack conveyance section 310 requires a change,there is no need to change the buffer unit 300 or the rack conveyancelogic.

Next, conveying a rack from the buffer unit 300 to the supplementalmodule 500 is described below using FIG. 16. The supplemental module 500in the present embodiment is disposed on the left side of the bufferunit 300 and has independent sample rack loading and unloadingpositions.

A sample rack to be unloaded into the supplemental module 500 is movedto the bucket 361 of the rack-moving mechanism 360, and then furthermoved to a rack-unloading position 501 in the supplemental module 500 byrotational driving of the Y-driving motor 364 of the rack-movingmechanism 360. After that, the rack-unloading mechanism 371 unloads thesample rack within the bucket 361 onto the conveyance line of thesupplemental module by pushing out the rack.

The sample rack that has been carried into the supplemental module isprovided with the necessary process, such as pipetting, at theprocessing position 502 and then moved to a rack unloading standbyposition 503 on the conveyance line.

At a sample rack unloading request from the rack unloading standbyposition 503, the rack-moving mechanism 360 of the buffer unit 300 movesthe bucket 361 to the rack unloading position 503 in the supplementalmodule by driving the Y-driving motor 364. A rack-unloading mechanism504 of the supplemental module moves the sample rack to the bucket 361after that.

Next, the conveyance of a sample rack which has been loaded from theone-rack loader/unloader 320 is described below.

Upon setup of a sample rack in the one-rack loader/unloader 320 by anoperator, the rack-moving mechanism 360 drives the Y-driving motor 364to move the bucket 361 to the one-rack loading/unloading position 320,and drives the X-driving motor 365 to move the carriage 363 upward tothe position of the sample rack. After this, the sample rack is moved tothe ID reading unit 372, by which the rack ID is then read. This isfollowed by movement of the sample rack to a sample vessel detector 373for sample vessel detection and sample ID reading. Data items ofprocessing in the functional module are determined from the rack ID andsample ID information that has been read. The sample rack that has gonethrough sample ID reading is moved to the bucket 361, then conveyed tothe functional module and the supplemental module in accordance with theabove-described conveying sequence, and undergoes processing. The samplerack thus processed is unloaded into the one-rack loader/unloader 320via the bucket 361 in essentially the same manner as that describedabove. This completes the conveyance of the rack.

Even if the sampler unit 100 or the rack conveyance line 200 becomesinoperable for reasons such as a failure, processing in the functionalmodule can be achieved by providing a sample rack loader/unloader suchas the one-rack loader/unloader 320 shown in the present embodiment, andas described earlier in this Specification, adopting a configurationwith independent supply lines for electric power, pure water, and otherutilities. In addition, sample racks standing by in the buffer 302 ofthe buffer unit 300, for example, can be unloaded from the one-rackloader/unloader 320 if the operator sends an unloading instruction froma switch or operating unit not shown.

Next, the cold-storage section 303 in which to make accuracy managementsamples stand by for processing is described below.

Accuracy management samples are samples whose data measurements arepredetermined to verify validity or correctness of the measurementresults obtained during analysis with the analyzer. Stability of theapparatus is confirmed by such verification. Accuracy management samplesare measured for each of the analytical items periodically, that is, atpreviously set intervals of time.

After being loaded from the sampler unit 100, a sample rack withaccuracy management samples set up therein is transferred to the bufferunit 300 by the rack transfer mechanism 330 thereof. The process flow upto this step is substantially the same as the above.

When the accuracy management sample rack that has been loaded into thebuffer unit 300 requires immediate analysis, the sample rack istransferred to the functional module 400 and the samples are analyzed.When immediate analysis is not required or after each sample has beenanalyzed in the functional module 400, the accuracy management samplerack is conveyed to the cold-storage section 303 for standby.

Since the accuracy management samples have predetermined datameasurements as described above, natural evaporation of these samplesduring prolonged standby in the analyzer causes changes in the datameasurements. For this reason, the cold-storage section 303 has acold-storage function to suppress the evaporation of the samples.

After a fixed time of analysis of a general-test sample, upon an arrivalat a time preset to measure an accuracy management sample for aparticular item, the accuracy management sample rack standing by in thecold-storage section 303 is conveyed therefrom to the functional module400 and the accuracy management sample is analyzed. After the analysis,the rack is reconveyed to the cold-storage section 303, in which therack then waits for a request for measurement of the next accuracymanagement sample.

The accuracy management sample rack standing by in the cold-storagesection 303 is unloaded therefrom under an operator instruction from theoperating unit and then stored into the storage section 102 of thebuffer unit 100 through the return lane 202 of the rack conveyance unit200.

Next, total system operation is described below.

FIG. 17 is a flowchart showing a method of determining sample rackconveyance routes.

Sample rack conveyance routes are determined upon completion of IDrecognition with the rack ID reading unit 104 and sample ID reading unit106 of the sampler unit 100, upon the unloading of the sample rack intothe module rack-unloading position 404 of the buffer unit 300 followingcompletion of processing in the functional module, and upon completionof ID recognition by the ID reader 321 provided to read the sample rackthat has been loaded from the one-rack loader/unloader 320.

A system control unit not shown manages load information on thefunctional modules that form part of the system, that is, the number ofsamples and analytical items to undergo processing in each functionalmodule. The system control unit also searches in the above timing forthe functional module whose load is the lightest of all module loads. Inaddition, the system control unit searches for items processable in thefunctional module. The load here includes processing capabilities ofeach functional module as well as the number of items to be processed ineach functional module, and is based upon, for example, a time up tocompletion of a preassigned task by the functional module, that is, thetime arithmetically derived by multiplying the number of processableitems by the time required for execution of the particular process.

The control unit judges whether an extracted functional module canconduct the necessary process for the rack. If the process in theextracted functional module is necessary, this module is determined as adestination to which the rack is to be moved, and the rack is conveyedto the destination.

If, as a result of the module search, a plurality of functional modulesidentical in load are present and the process for the rack is to beconducted in each of these modules, the functional module nearest to acurrent position of the rack is determined as the destination thereof.

If the process in the functional module which has been extracted becauseof the lightest load is unnecessary, the control unit searches for thefunctional module of the next lowest load, and for items processable inthis module, and judges once again whether the necessary process can beconducted for the rack. This sequence is repeated for all functionalmodules and whether each module can be a destination for the rack.

If none of the functional modules is eventually found to be fit for useas the destination of the rack, the control unit judges whether the rackrequires automatic retesting. If automatic retesting is required, therack is moved to the buffer of the buffer unit and waits for analyticalresults to be output. After the output of the analytical results, ifretesting is necessary, the rack is reconveyed from the buffer to theprocessing position in the functional module. After being processed, therack is unloaded from the buffer unit and stored into the storagesection of the sampler unit through the return lane of the rackconveyance section. If automatic retesting is unnecessary or ifautomatic retesting, although it has once been judged to be necessaryand the rack has been placed in the buffer for standby, is newly judgedfrom output results not to be necessary, the rack is stored from thebuffer unit into the storage section similarly to the above.

Load information on each functional module is updated upon detection ofa change in load, that is, upon the determination of a new destinationfor the sample rack, or upon the unloading thereof into the modulerack-unloading position of the buffer unit following an end of theprocess in the functional module.

Examples of actual sample rack flow are described below. FIGS. 18 and 19are schematic diagrams of a system which includes a sampler unit 100, arack conveyance line 200, buffer units 300 a, 300 b, 300 c, functionalmodules 400 a, 400 b, 400 c, and a supplemental module 500.

A case in which a sample rack requires no processing in the functionalmodule 400 a and the supplemental module 500, a load upon the functionalmodule 400 a is the lightest of all loads upon the functional modules400 a, 400 b, 400 c and the supplemental module 500, and automaticretesting is unnecessary, is described as an example below using FIG.18.

In this case, processing items on the sample rack loaded into thesampler unit 100 are determined from the corresponding rack ID andsample ID information in the same manner as that described above. Duringthe determination, the control unit searches for the functional modulewith the lightest load, and for items processable in this functionalmodule. The functional module 400 a is determined as a conveyancedestination since the module 400 a is first extracted on the basis ofits load information and since the rack requires processing in themodule 400 a. In accordance with the determination, the sample rack istransferred from a rack loading/unloading position 203 a through thefeed lane 201 of the rack conveyance unit 200 to the buffer unit 300 a.

At this time, if the functional module 400 a to which the sample rackhas been transferred is ready to immediately process the rack, that is,if an internal buffer 403 a of the module 400 a is not full, the rack isconveyed to the module 400 a. If the functional module 400 a is notready for immediate rack processing, the sample rack is conveyed to abuffer 302 a.

After the sample rack has moved to the buffer unit 300 a, a conveyanceroute of the next sample rack loaded from the sampler unit is determinedin substantially the same manner as that described above. When thefunctional module 400 a is determined as the conveyance destination ofthe next sample rack for substantially the same reason as the above, ifthe total number of sample racks present in and between the buffer unit300 a and functional module 400 a or supplemental module 500 on theconveyance route at that time is less than the number of slots in thebuffer 302 a of the buffer unit 300 a, the loading of the next samplerack into the buffer unit 300 a is continued and the sample rack is madeto stand by in an empty slot of the buffer 302 a. If the total number ofsample racks is equal to the number of slots in the buffer, the samplerack is made to stand by in the sampler unit until sample rack unloadingfrom the buffer unit 300 a into the conveyance unit 200 has beencompleted.

When a vacancy occurs in the buffer 403 a of the module 400 a, thesample rack that has been made to stand by in the buffer 302 a isconveyed to functional modules, sequentially processed in each of themodules, and unloaded into a module rack-unloading position 404 a of thebuffer unit 300 a. At this point of time, the next conveyance route isdetermined for the rack. If the loads of the functional module 400 b,the supplemental module 500, and the functional module 400 c are lighterin that order, the control unit extracts the functional module 400 b.However, since the rack requires no processing in 400 b, the controlunit next extracts the supplemental module 500 whose load is lighterthan that of 400 b. Since the rack requires processing in thesupplemental module 500, this module is determined as the nextconveyance destination.

At this time, if the supplemental module 500 is ready for immediate rackprocessing, the rack is conveyed directly to the supplemental module500. If the supplemental module is not ready for immediate processing,the sample rack stands by in the buffer 302 a and after the supplementalmodule has become ready, the rack is conveyed to the module.

The rack that has gone through the process in the supplemental module500 is unloaded into the rack-unloading position 503 thereof. This isfollowed by the next conveyance routing. Since all necessary processingof the rack is already completed, however, the storage section 102 ofthe sampler unit 100 is determined as the next conveyance destination.In accordance with the determination, the buffer unit 300 activates thetransfer mechanism to move the sample rack to the rack loading/unloadingposition 204 a on the return lane 202 of the rack conveyance unit 200,and then the rack conveyance unit 200 stores the rack into the storagesection.

A case in which a sample rack requires processing in the functionalmodules 400 a, 400 b, 400 c, the load of the functional module 400 c isthe lightest of all loads upon each functional module and thesupplemental module 500, and automatic retesting in the functionalmodule 400 b is necessary, is described as another example below usingFIG. 19.

In accordance with the flowchart of FIG. 17, the functional module 400 cwith the lightest load is determined as a first conveyance destinationfor the sample rack which has been loaded into the sampler unit 100. Theloaded sample rack is moved to the rack loading/unloading position 203c, along the feed lane 201 of the rack conveyance unit 200, and afterthe rack has undergone processing in the functional module 400 c via thebuffer unit 300 c, the next conveyance route is determined at the rackunloading position 404 c of the module.

If the loads of the functional modules 400 a and 400 b at this point oftime are the same, the functional module 400 b nearest to the functionalmodule 400 c is determined as the next conveyance destination of thesample rack. Therefore, the rack is unloaded into a rackloading/unloading position 204 c on the return lane 202 of the rackconveyance unit 200 via the buffer unit 300 c, then moved to the rackloading/unloading position 204 b in the buffer unit 300 b through thereturn lane 202, and processed in the functional module 400 b via thebuffer unit 300 b. After rack processing, the next conveyance route isdetermined at the rack-unloading position 404 b of the module.

If the load of the functional module 400 a is the lightest of all moduleloads at this time, the module 400 a is determined as the conveyancedestination for the same reason as described above. The rack is unloadedinto the rack loading/unloading position 204 b on the return lane 202 ofthe rack conveyance unit 200 via the buffer unit 300 b, then moved tothe rack loading/unloading position 204 a in the buffer unit 300 athrough the return lane 202, and processed in the functional module 400a via the buffer unit 300 a. After rack processing, the next conveyanceroute is determined at the rack-unloading position 404 a of the module.

At this time, a conveyance destination is extracted in accordance withthe flowchart of FIG. 17. If, at this time, initial measurement resultsare already obtained in the functional module 400 b and indicate thatretesting is necessary, the functional module 400 b is determined as theconveyance destination. Conversely if initial measurement results arenot obtained and it is unknown whether retesting is necessary, the rackstands by in the buffer 302 a of the buffer unit 300 a.

If retesting is necessary, the rack is unloaded into the rackloading/unloading position 203 a on the feed lane 201 of the rackconveyance unit 200 via the buffer unit 300 a, then moved to the rackloading/unloading position 203 b in the buffer unit 300 b through thefeed lane 201, and retested in the functional module 400 b. Theretesting of the rack is followed by the next conveyance routing at themodule rack-unloading position 404 b.

At this time, the next conveyance destination is extracted in accordancewith the flowchart of FIG. 17. Since all processing required for therack is already completed, the storage section 102 of the sampler unit100 is determined as the next conveyance destination. Therefore, therack is unloaded into the rack loading/unloading position 204 b on thereturn lane 202 of the rack conveyance unit 200 through the buffer unit300 b, and stored into the storage section 102 of the sampler unit 100through the feed lane 202.

Conversely if retesting is not required, the storage section 102 of thesampler unit 100 is determined as the conveyance destination of the rackwhich has been standing by in the buffer 302 a of the buffer unit 300 a.After this, the rack is unloaded into the rack loading/unloadingposition 204 a on the return lane 202 of the rack conveyance unit 200via the buffer unit 300 b, and stored into the storage section 102 ofthe sampler unit 100 through the feed lane 201.

Next, process flow relating to a loaded emergency-test sample isdescribed below using FIG. 20. For simplicity, the description assumesthat the emergency-test sample requires processing by the functionalmodule 400 a only.

The ID of the emergency-test sample rack 553 which has been loaded intothe emergency-test sample loader 109 of the sampler unit 100 is read,then the functional module 400 a is determined as a conveyancedestination, and the rack is loaded from the rack loading/unloadingposition 203 a of the buffer unit 300 a into a rack loading/unloadingposition 301 a of the buffer unit 300 a. Upon recognizing that theemergency-test sample will soon be loaded, the buffer unit 300 a and thefunctional module 400 a start operating to move a general-test samplerack 550, 551, or 552 from the conveyance route to the buffer 302 a.When the conveyance route to the functional module 400 a becomesuseable, the emergency-test sample rack 553 is immediately conveyedthereto for processing. Upon the conveyance of the emergency-test samplerack 553 to the functional module 400 a, the general-test sample rack550, 551, 552 is reconveyed thereto and processing is restarted. Theemergency-test sample rack 553 whose processing has ended is stored intothe storage section 102 in accordance with the flowchart of FIG. 17.

What is claimed is:
 1. A sample-processing system capable for connectinga plurality of functional modules comprising: at least one functionalmodule; a loader for loading sample racks; a conveyance unit forconveying the sample racks loaded in the loader to the at least onefunctional module; a control unit for controlling the conveyance unit; afirst buffer unit included in each functional module, causing the sampleracks to standby while waiting a dispensing process at a dispensingposition; and a second buffer unit arranged at a side of the loader, thesecond buffer unit being paired with the first buffer unit, wherein thesecond buffer unit includes a plurality of slots for the sample racks ontemporarily standby before the sample racks are conveyed to thedispensing position, the conveyance unit conveys the sample racks loadedin the loader to the first buffer unit and the slots of the secondbuffer unit, the control unit is programmed to: determine whether or notthe first buffer unit is filled with the sample racks, when the sampleracks loaded in the loader are conveyed to the functional module, conveythe sample racks to the first buffer unit not to convey the sample racksto the second buffer unit in case that the first buffer unit is notfilled with the sample racks, and convey the sample racks to the slotsof the second buffer unit for the sample racks on temporarily standbybefore the sample racks are conveyed to the first buffer unit in casethat the first buffer unit is filled with the sample racks.
 2. Thesample-processing system according to claim 1, wherein the second bufferunit is arranged at the loader side relative to the first buffer unit.3. The sample-processing system according to claim 1, wherein theconveyance unit includes a conveyance section for conveying the sampleracks in an X direction, conveying the sample racks loaded in the loaderin the X direction and a Y direction, and the conveyance unit conveysthe sample racks loaded in the loader in the X direction and the Ydirection, so that the sample racks loaded in the loader are conveyed tothe first buffer unit and the slots of the second buffer unit, and thesecond buffer unit is arranged near to the conveyance unit in the Ydirection.
 4. The sample-processing system according to claim 1, whereinthe conveyance unit conveys the sample racks to a position in a firstdirection and a position out of the first direction, so that theconveyance unit conveys the sample racks loaded in the loader to thefirst buffer unit and the slots of the second buffer unit, and thesecond buffer unit is arranged at a position out of a route of the firstdirection.
 5. The sample-processing system according to claim 1, whereinthe control unit is programmed to control the conveyance unit to conveythe sample racks temporarily waited in the slots of the second bufferunit to the first buffer unit at a time point when a space occur in thefirst buffer unit.
 6. The sample-processing system according to claim 5,wherein the control unit is further programmed to: control theconveyance unit to convey the sample racks to the first buffer unitcontinuously until the first buffer unit is filled with the sampleracks.
 7. The sample-processing system according to claim 1, furthercomprising a plurality of slot positions for loading the sample racks,the plurality of slot positions corresponding to the polarity of slotsincluded in the second buffer unit, wherein the control unit is furtherprogrammed to: control the conveyance unit to move the sample racks tothe slots corresponding to the plurality of the slot positions after thesample racks are moved to the slot positions corresponding to the slotsto be used for standby of the sample racks.
 8. The sample-processingsystem according to claim 1, wherein the control unit is furtherprogrammed to: control the conveyance unit to convey the sample racksbetween the first buffer unit and the slots of the second buffer unitdirectionally, and control the second buffer unit to maintain standbycondition of the sample racks in the slots for the sample racks whosesamples are not processed for dispensing process and the sample rackswhose samples are required to be retested and already processed fordispensing process.
 9. The sample-processing system according to claim1, wherein the control unit is further programmed to: control theconveyance unit to temporarily and upwardly move the sample racks to betemporarily standby in the second buffer unit and to convey the sampleracks to the second buffer unit.
 10. The sample-processing systemaccording to claim 1, wherein the second buffer unit is included insideof the functional module having the first buffer unit paired to thesecond buffer unit.
 11. The sample-processing system according to claim1, comprising a plurality of functional modules are connected to thesample-processing system.
 12. A functional module of a sample-processingsystem having a loader for loading sample racks, a conveyance unit forconveying the sample racks loaded in the loader, and a control unit forcontrolling the conveyance unit, the functional module comprising: afirst buffer unit for causing the sample racks to standby while waitinga dispensing process at a dispensing position; and a second buffer unitincluding a plurality of slots for the sample racks on temporarilystandby before the sample racks are conveyed to the dispensing position,wherein the second buffer unit is arranged at a side of the loader, thesample racks loaded in the loader are conveyed to the first buffer unitand the slots of the second buffer unit by the conveyance unit, whetheror not the first buffer unit is filled with the sample racks isdetermined by the control unit, when the sample racks loaded in theloader are conveyed to the functional module, the first buffer unitreceives the sample racks not to be conveyed to the second buffer uniton a basis of the control of the control unit in case that the firstbuffer unit is not filled with the sample racks on the basis of thecontrol of the control unit, and the slots of the second buffer unitreceives the sample racks conveyed to the slots of the second bufferunit before the sample racks are conveyed to the first buffer unit onthe basis of the control of the control unit in case that the firstbuffer unit is filled with the sample racks.
 13. The functional moduleaccording to claim 12, wherein the conveyance unit includes a conveyancesection for conveying the sample racks in an X direction, conveying thesample racks loaded in the loader in the X direction and a Y direction,and the conveyance unit conveys the sample racks loaded in the loader inthe X direction and the Y direction, so that the sample racks loaded inthe loader are conveyed to the first buffer unit and the slots of thesecond buffer unit, and the second buffer unit is arranged near to theconveyance unit in the Y direction.
 14. The functional module accordingto claim 12, wherein the conveyance unit conveys the sample racks to aposition in a first direction and a position out of the first direction,so that the conveyance unit conveys the sample racks loaded in theloader to the first buffer unit and the slots of the second buffer unit,and the second buffer unit is arranged at a position out of a route ofthe first direction.
 15. The functional module according to claim 12,wherein the control unit is programmed to: control the conveyance unitto convey the sample racks temporarily waited in the slots of the secondbuffer unit to the first buffer unit at a time point when a space occurin the first buffer unit.
 16. The functional module according to claim15, wherein the control unit is programmed to: control the conveyanceunit to convey the sample racks to the first buffer unit continuouslyuntil the first buffer unit is filled with the sample racks.
 17. Thefunctional module according to claim 12, further comprising a pluralityof slot positions for loading the sample racks, the plurality of slotpositions corresponding to the polarity of slots included in the secondbuffer unit, wherein the control unit is programmed to: control theconveyance unit to move the sample racks to the slots corresponding tothe plurality of the slot positions after the sample racks are moved tothe slot positions corresponding to the slots to be used for standby ofthe sample racks.
 18. The functional module according to claim 12,wherein the control unit is programmed to: control the conveyance unitto convey the sample racks between the first buffer unit and the slotsof the second buffer unit directionally, and control the second bufferunit to maintain standby condition of the sample racks in the slots forthe sample racks whose samples are not processed for dispensing processand the sample racks whose samples are required to be retested andalready processed for dispensing process.
 19. The functional moduleaccording to claim 12, wherein the control unit is programmed to:control the conveyance unit to temporarily and upwardly move the sampleracks to be temporarily standby in the second buffer unit and to conveythe sample racks to the second buffer unit.